Semiconductor structure and method of forming the same

Abstract

A semiconductor structure and a method of forming the same, wherein the structure comprises: a substrate; a magnetic tunnel junction on the substrate, the magnetic tunnel junction comprising a first region and a second region adjacent to each other, the magnetic tunnel junction comprising a plurality of layers of materials stacked along a normal direction of the substrate, and at least one layer of the materials in the first region is different from at least one layer of the materials in the second region. The semiconductor structure has a high storage capacity density.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a semiconductor structure and a method for forming the same. Background Technology

[0002] MRAM (Magnetic Random Access Memory) is a non-volatile magnetic random access memory. It possesses the high-speed read / write capabilities of Static Random Access Memory (SRAM) and the high integration density of Dynamic Random Access Memory (DRAM), while consuming significantly less power than DRAM. Compared to Flash memory, its performance does not degrade over time. Due to these characteristics, MRAM is called universal memory and is considered a viable replacement for SRAM, DRAM, EEPROM, and Flash.

[0003] Unlike traditional random access memory (RAM) chip fabrication techniques, data in MRAM is not stored as charge or current, but rather as a magnetic state, sensed by measuring resistance without interfering with this magnetic state. MRAM uses a magnetic tunnel junction (MTJ) structure for data storage. Generally, an MRAM cell consists of a transistor (1T) and an MTJ, forming a storage unit. The MTJ structure includes at least two electromagnetic layers and an insulating layer to isolate the two layers. Current flows perpendicularly from one electromagnetic layer through the insulating layer or "passes" through the other. One electromagnetic layer is a fixed magnetic layer, using a strong fixing field to hold the electrodes in a specific orientation. The other electromagnetic layer is a freely rotatable magnetic layer, holding the electrodes to one side.

[0004] However, the capacity density of magnetic random access memories fabricated using existing technologies is poor. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a semiconductor structure and a method for forming the same, so as to improve the storage capacity density of the formed semiconductor structure.

[0006] To solve the above-mentioned technical problems, the present invention provides a semiconductor structure, comprising: a substrate; a magnetic tunnel junction located on the substrate, the magnetic tunnel junction comprising adjacent first and second regions, the magnetic tunnel junction comprising multiple layers of material overlapping along the normal direction of the substrate, and at least one material layer in the first region and the material layer in the second region being different.

[0007] Optionally, the different material layers may have different physical or chemical properties.

[0008] Optionally, the multilayer material includes: a first electromagnetic layer, an insulating layer located on the surface of the first electromagnetic layer, and a second electromagnetic layer located on the surface of the insulating layer.

[0009] Optionally, the thickness of the first electromagnetic layer in the first region is different from the thickness of the first electromagnetic layer in the second region.

[0010] Optionally, the roughness of the first electromagnetic layer in the first region is different from the roughness of the first electromagnetic layer in the second region.

[0011] Optionally, the material of the first electromagnetic layer in the first region includes cobalt iron boron, and the material of the first electromagnetic layer in the second region includes cobalt iron boron doped with a first modified ion, wherein the first modified ion includes titanium ions or tantalum ions.

[0012] Optionally, the thickness of the insulating layer in the first region is different from the thickness of the insulating layer in the second region.

[0013] Optionally, the roughness of the insulating layer in the first region is different from that in the second region.

[0014] Optionally, the insulating layer of the first region is made of magnesium oxide, and the insulating layer of the second region is made of magnesium oxide doped with a second modified ion, wherein the second modified ion is nitrogen ion or magnesium ion.

[0015] Optionally, the thickness of the second electromagnetic layer in the first region is different from the thickness of the second electromagnetic layer in the second region.

[0016] Optionally, the roughness of the second electromagnetic layer in the first region is different from the roughness of the second electromagnetic layer in the second region.

[0017] Optionally, the material of the second electromagnetic layer in the first region includes cobalt iron boron, and the material of the second electromagnetic layer in the second region includes cobalt iron boron doped with a third ion, wherein the third modified ion includes titanium ions or tantalum ions.

[0018] Optionally, the multilayer material layer may further include a seed layer located at the bottom of the first electromagnetic layer.

[0019] Optionally, the thickness of the seed layer in the first region is different from the thickness of the seed layer in the second region.

[0020] Optionally, the roughness of the seed layer in the first region is different from that in the seed layer in the second region.

[0021] Optionally, the seed layer material of the first region includes cobalt iron boron, and the seed layer material of the second region includes cobalt iron boron doped with a fourth modified ion, wherein the fourth modified ion includes titanium ions or tantalum ions.

[0022] Optionally, the multilayer material layer may further include an optimization layer located on the second electromagnetic layer.

[0023] Optionally, the thickness of the optimization layer in the first region is different from the thickness of the optimization layer in the second region.

[0024] Optionally, the roughness of the optimization layer in the first region is different from that in the optimization layer in the second region.

[0025] Optionally, the material of the optimized layer in the first region includes cobalt iron boron, and the material of the optimized layer in the second region includes cobalt iron boron doped with a fifth modified ion, wherein the fifth modified ion includes nitrogen ions or magnesium ions.

[0026] Optionally, the multilayer material layer further includes: a lower electrode layer located at the bottom of the first electromagnetic layer and an upper electrode layer located on the second electromagnetic layer.

[0027] Optionally, the thickness of the lower electrode layer in the first region is different from the thickness of the lower electrode layer in the second region.

[0028] Optionally, the roughness of the lower electrode layer in the first region is different from that in the lower electrode layer in the second region.

[0029] Optionally, the material of the lower electrode layer in the first region includes a metal, and the material of the lower electrode layer in the second region includes a metal doped with a sixth modified ion, wherein the sixth modified ion includes a titanium ion or a tantalum ion.

[0030] Optionally, the thickness of the upper electrode layer in the first region is different from the thickness of the upper electrode layer in the second region.

[0031] Optionally, the roughness of the upper electrode layer in the first region is different from that in the upper electrode layer in the second region.

[0032] Optionally, the material of the upper electrode layer in the first region includes a metal, and the material of the upper electrode layer in the second region includes a metal doped with a seventh modified ion, wherein the seventh modified ion includes a titanium ion or a tantalum ion.

[0033] Optionally, the magnetic tunnel junction further includes a third region adjacent to the first and second regions, wherein at least one material layer in the third region is different from the material layers in the first and second regions.

[0034] Accordingly, the present invention provides a method for forming a semiconductor structure, comprising: providing a substrate; forming a magnetic tunnel junction on the substrate, the magnetic tunnel junction comprising an adjacent first region and a second region, the magnetic tunnel junction comprising multiple layers of material overlapping along the normal direction of the substrate, and at least one material layer of the first region and the material layer of the second region being different.

[0035] Optionally, the multilayer material includes: a first electromagnetic layer, an insulating layer located on the surface of the first electromagnetic layer, and a second electromagnetic layer located on the surface of the insulating layer.

[0036] Optionally, the substrate includes a plurality of initial first regions, with initial second regions between adjacent initial first regions, and the initial second regions and initial first regions are adjacent; the method for forming the multilayer material layer includes: forming a first electromagnetic material film on the initial first regions and initial second regions; forming an insulating material film on the second electromagnetic material film; forming a second electromagnetic material film on the insulating material film; using a patterning process, etching the first electromagnetic material film, the insulating material film, and the second electromagnetic material film until the substrate surface is exposed, forming the magnetic tunnel junction on the substrate, wherein the first region of the magnetic tunnel junction is located on a portion of the initial first regions, the second region of the magnetic tunnel junction is located on the portion of the initial second regions, and the magnetic tunnel junction includes: a first electromagnetic layer, an insulating layer located on the first electromagnetic layer, and a second electromagnetic layer located on the insulating layer.

[0037] Optionally, the patterning process includes: forming a first patterned layer on the second electromagnetic material film, wherein the first patterned layer exposes a portion of the second electromagnetic material film; using the first patterned layer as a mask, etching the first electromagnetic material film, the insulating material film, and the second electromagnetic material film until the substrate surface is exposed.

[0038] Optionally, the method for forming the multilayer material layer further includes: modifying at least one of the first electromagnetic material film, the insulating material film, and the second electromagnetic material film.

[0039] Optionally, the modification process includes: forming a second patterned layer on the surface of the first electromagnetic material film; the second patterned layer exposing the surface of the first electromagnetic material film on the initial first region or the initial second region; and using the second patterned layer as a mask to modify the first electromagnetic material film.

[0040] Optionally, the modification process includes: forming a third patterned layer on the surface of the insulating material film; the third patterned layer exposing the surface of the insulating material film on the initial first region or the initial second region; and using the third patterned layer as a mask to modify the insulating material film.

[0041] Optionally, the modification process includes: forming a fourth patterned layer on the surface of the second electromagnetic material film; the fourth patterned layer exposing the surface of the second electromagnetic material film on the initial first region or the initial second region; and using the fourth patterned layer as a mask to modify the second electromagnetic material film.

[0042] Optionally, the modification treatment includes one or a combination of physical modification and chemical modification.

[0043] Optionally, the physical modification method includes plasma etching.

[0044] Optionally, the physical modification method includes a chemical etching process.

[0045] Optionally, the chemical modification method includes: plasma doping treatment, wherein the doped ions include: titanium ions, magnesium ions, nitrogen ions, or magnesium ions.

[0046] Optionally, the chemical modification method includes: chemical solution treatment.

[0047] Optionally, the method for forming the multilayer material layer further includes: forming a seed material film on the substrate before forming the first electromagnetic material film; the patterning process further etches the seed material film to form a seed layer in a first region and a second region.

[0048] Optionally, it may also include: after forming the seed material film and before the patterning process, modifying the seed material film so that the seed material films on the initial first region and the initial second region are different.

[0049] Optionally, the method for forming the multilayer material layer further includes: after forming the second electromagnetic material film, forming an optimized material film on the surface of the second electromagnetic material film; and etching the optimized material film by the patterning process to form an optimized layer in the first region and the second region.

[0050] Optionally, it may also include: after forming the optimized material film and before the patterning layer process, modifying the optimized material film so that the optimized material films on the initial first region and the initial second region are different.

[0051] Optionally, the method for forming the multilayer material layer further includes: forming a lower electrode material film on the substrate before forming the first electromagnetic material film; forming an upper electrode material film on the second electromagnetic material film after forming the second electromagnetic material film; the patterning process further etches the lower electrode material film and the upper electrode material film to form a lower electrode layer and an upper electrode layer in a first region and a second region, wherein the lower electrode layer is located at the bottom of the first electromagnetic layer and the upper electrode layer is located on the second electromagnetic layer.

[0052] Optionally, it may also include: modifying the lower electrode material film to make the materials of the lower electrode material films on the initial first region and the initial second region different.

[0053] Optionally, it may also include: modifying the upper electrode material film to make the materials of the upper electrode material films on the initial first region and the initial second region different.

[0054] Optionally, the magnetic tunnel junction further includes a third region adjacent to the first and second regions, wherein at least one material layer on the third region is different from the material layers of the first and second regions.

[0055] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0056] In the semiconductor structure provided by the present invention, since the magnetic tunnel junction includes adjacent first and second regions, and at least one material layer in the first region and the material layer in the second region are different, the multilayer material layers in the first region and the multilayer material layers in the second region have different high resistance and low resistance values, respectively. Furthermore, the magnetic resistances of the first and second regions are connected in parallel, allowing the magnetic tunnel junction to form a 2^ n This allows for the creation of multiple states (n being a natural number greater than 1), thereby effectively increasing the storage capacity of a single memory cell and consequently improving the storage capacity density of the resulting semiconductor structure.

[0057] In the semiconductor structure formation method provided by the present invention, a magnetic tunnel junction is formed on a substrate. The magnetic tunnel junction includes adjacent first and second regions, and at least one material layer in the first region and the material layer in the second region are different, so that the multilayer material layers in the first region and the multilayer material layers in the second region have different high resistance and low resistance values, respectively. Furthermore, the magnetic resistances of the first region and the second region are connected in parallel, allowing the magnetic tunnel junction to be formed at a density of 2^... n This allows for the creation of multiple states (n being a natural number greater than 1), thereby effectively increasing the storage capacity of a single memory cell and consequently improving the storage capacity density of the resulting semiconductor structure. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of a semiconductor structure.

[0059] Figure 2 This is a schematic diagram of a semiconductor structure.

[0060] Figures 3 to 18 This is a schematic diagram of the steps in a semiconductor structure formation method according to an embodiment of the present invention. Detailed Implementation

[0061] First, the performance of existing semiconductor structures will be described in detail with reference to the accompanying drawings. Figure 1 This is a schematic diagram of a semiconductor structure.

[0062] Please refer to Figure 1 A substrate 10; a plurality of magnetic tunnel junctions 11 located on the substrate 10.

[0063] By reducing the spacing between magnetic tunnel junctions 11, the number of magnetic tunnel junctions 11 within a certain area can be increased, thereby increasing the storage capacity density of the formed semiconductor structure.

[0064] However, as the integration requirements of semiconductor devices become increasingly stringent, the spacing between adjacent magnetic tunnel junctions 11 is already quite small. Further reducing the spacing could easily exceed the limits of existing photolithography processes and increase the complexity of the process.

[0065] Figure 2 This is a schematic diagram of a semiconductor structure.

[0066] To address the above problems, a semiconductor structure is proposed. Please refer to [reference needed]. Figure 2 It includes: a substrate 20; a first magnetic tunnel junction 21 and a second magnetic tunnel junction 22 that are superimposed on the substrate 20 along the normal direction of the substrate 20.

[0067] In the above structure, the first magnetic tunnel junction 21 and the second magnetic tunnel junction 22 are electrically connected and can function as a memory cell. Furthermore, the first magnetic tunnel junction 21 and the second magnetic tunnel junction 22 have different switching voltages, increasing the storage capacity of a single memory cell. However, the first magnetic tunnel junction 21 and the second magnetic tunnel junction 22 are connected in series, resulting in higher resistance in both junctions and requiring a stronger driving voltage, thus degrading the performance of the semiconductor structure.

[0068] To address the aforementioned technical problems, embodiments of the present invention provide a method for forming a semiconductor structure, comprising: providing a substrate; forming a magnetic tunnel junction on the substrate, wherein the magnetic tunnel junction includes adjacent first and second regions, and the magnetic tunnel junction includes multiple layers of material overlapping along the normal direction of the substrate, wherein at least one material layer of the first region and the material layer of the second region are different, which is beneficial to improving the storage capacity density of the formed semiconductor structure.

[0069] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0070] Figures 3 to 18 This is a schematic diagram of the steps in a semiconductor structure formation method according to an embodiment of the present invention.

[0071] Please refer to Figure 3 Provides a base of 200.

[0072] In this embodiment, the substrate 200 includes a plurality of initial first regions A, and an initial second region B is located between adjacent initial first regions A, and the initial second region B and the initial first region A are adjacent to each other.

[0073] In this embodiment, the substrate 200 includes a substrate (not shown) and a device layer (not shown) located on the surface of the substrate. The device layer may include device structures, such as PMOS transistors and NMOS transistors. The device layer may also include interconnect structures electrically connected to the device structures, and an insulating layer surrounding the device structures and the interconnect structures.

[0074] The substrate 200 is made of a semiconductor material. In this embodiment, the substrate 200 is made of silicon. In other embodiments, the substrate material includes silicon carbide, silicon germanium, a multi-element semiconductor material composed of group III-V elements, silicon-on-insulator (SOI), or germanium-on-insulator. The multi-element semiconductor material composed of group III-V elements includes InP, GaAs, GaP, InAs, InSb, InGaAs, or InGaAsP.

[0075] Next, a magnetic tunnel junction is formed on the substrate 200. The magnetic tunnel junction includes adjacent first and second regions. The magnetic tunnel junction includes multiple layers of material overlapping along the normal direction of the substrate 200, and at least one material layer of the first region and the material layer of the second region are different. In this embodiment, the multiple material layers include: a lower electrode layer on the substrate 200, a seed layer on the surface of the lower electrode layer, a first electromagnetic layer on the surface of the seed layer, an insulating layer on the surface of the first electromagnetic layer, a second electromagnetic layer on the surface of the insulating layer, an optimization layer on the surface of the second electromagnetic layer, and an upper electrode layer on the surface of the optimization layer. For a detailed description of the process of forming the magnetic tunnel junction, please refer to [reference needed]. Figures 4 to 18 .

[0076] Please refer to Figure 4 A lower electrode material film 210 is formed on the substrate 200.

[0077] The formation process of the lower electrode material film 210 includes physical vapor deposition or chemical vapor deposition.

[0078] The material of the lower electrode material film 210 includes one or a combination of titanium, tantalum, platinum, copper, tungsten, aluminum, titanium nitride, tantalum nitride, and tungsten silicide.

[0079] In this embodiment, the material of the lower electrode material film 210 is tungsten.

[0080] In this embodiment, the lower electrode material film 210 on the initial first region A and the lower electrode material film 210 on the initial second region B are the same.

[0081] In other embodiments, the method for forming the semiconductor structure further includes: modifying the lower electrode material film to make the lower electrode material film on the initial first region different from the lower electrode material film on the initial second region.

[0082] In one embodiment, the thickness of the lower electrode material film on the initial first region is different from the thickness of the lower electrode material film on the initial second region.

[0083] In another embodiment, the roughness of the lower electrode material film on the initial first region is different from the roughness of the lower electrode material film on the initial second region.

[0084] In another embodiment, the material of the lower electrode material film on the initial first region is tungsten, and the material of the lower electrode material film on the initial second region is tungsten doped with a sixth modified ion, the sixth modified ion including titanium ions or tantalum ions.

[0085] Please refer to Figure 5 A seed material film 220 is formed on the surface of the lower electrode material film 210.

[0086] The seed material film 220 can better match the lattice of the subsequently formed upper electrode material film, thereby improving the performance of the formed magnetic tunnel junction.

[0087] The formation process of the seed material film 220 includes physical vapor deposition or chemical vapor deposition.

[0088] The seed material membrane 220 is made of one or more of the following materials: iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron, and lanthanum strontium manganese oxide.

[0089] In this embodiment, the seed material film 220 is made of cobalt iron boron.

[0090] In this embodiment, the seed material film 220 on the initial first region A and the seed material film 220 on the initial second region B are the same.

[0091] In other embodiments, the method for forming the semiconductor structure further includes: modifying the lower electrode material film to make the seed material film on the initial first region different from the seed material film on the initial second region.

[0092] In one embodiment, the thickness of the seed material film on the initial first region is different from the thickness of the seed material film on the initial second region.

[0093] In another embodiment, the roughness of the seed material film on the initial first region is different from the roughness of the seed material film on the initial second region.

[0094] In another embodiment, the seed material film on the initial first region is made of cobalt iron boron, and the seed material film on the initial second region is made of cobalt iron boron doped with a fourth modified ion, which includes titanium ions or tantalum ions.

[0095] Please refer to Figure 6 A first electromagnetic material film 230 is formed on the surface of the seed material film 220.

[0096] The formation process of the first electromagnetic material film 230 includes physical vapor deposition or chemical vapor deposition.

[0097] The material of the first electromagnetic material film 230 includes one or a combination of iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron, and lanthanum strontium manganese oxide.

[0098] In this embodiment, the material of the first electromagnetic material film 230 is cobalt iron boron.

[0099] Next, the first electromagnetic material film 230 is modified. For details of the modification process, please refer to [reference needed]. Figures 7 to 8 .

[0100] Please refer to Figure 7 A second patterned layer 231 is formed on the surface of the first electromagnetic material film 230; the second patterned layer 231 exposes the surface of the first electromagnetic material film 230 on the initial first region A or the initial second region B.

[0101] In this embodiment, the second patterned layer 231 exposes the surface of the first electromagnetic material film 230 on the initial second region B.

[0102] In other embodiments, the second patterned layer exposes the surface of the first electromagnetic material film on the initial first region.

[0103] Please refer to Figure 8 Using the second patterned layer 231 as a mask, the first electromagnetic material film 230 is modified.

[0104] The modification treatment includes one or a combination of physical modification and chemical modification.

[0105] In this embodiment, the modification process used is physical modification.

[0106] In this embodiment, the physical modification method is a plasma etching process, and the process parameters of the plasma etching include: the gas used includes Ar, Xe or Kr.

[0107] In this embodiment, after the plasma etching process, the thickness of the first electromagnetic material film 230 on the initial first region A is different from the thickness of the first electromagnetic material film 230 on the initial second region B.

[0108] In other embodiments, the physical modification method is a chemical etching process, or the modification treatment may also be chemical modification.

[0109] In another embodiment, after the modification treatment, the roughness of the first electromagnetic material film on the initial first region is different from the roughness of the first electromagnetic material film on the initial second region.

[0110] In another embodiment, after the modification treatment, the material of the first electromagnetic material film on the initial first region is cobalt iron boron, and the material of the first electromagnetic material film on the initial second region is cobalt iron boron doped with a first modifying ion, wherein the second modifying ion includes titanium ions or tantalum ions.

[0111] In this embodiment, after modifying the first electromagnetic material film 230, the second patterned layer 231 is removed.

[0112] In other embodiments, the first electromagnetic material film may not be modified, and the first electromagnetic material film on the initial first region may be the same as the first electromagnetic material film on the initial second region.

[0113] Please refer to Figure 9 An insulating material film 240 is formed on the surface of the first electromagnetic material film 230.

[0114] The process for forming the insulating material film 240 includes physical vapor deposition or chemical vapor deposition.

[0115] The insulating material film 240 is made of one or more of the following materials: magnesium oxide, aluminum oxide, silicon nitride, silicon oxynitride, hafnium dioxide, and zirconium dioxide.

[0116] In this embodiment, the insulating material film 240 is made of magnesium oxide.

[0117] Next, the insulating material film 240 undergoes a modification treatment. For details of the modification treatment process, please refer to [link / reference needed]. Figures 10 to 11 .

[0118] Please refer to Figure 10A third patterned layer 241 is formed on the surface of the insulating material film 240; the third patterned layer 241 exposes the surface of the insulating material film on the initial first region A or the initial second region B.

[0119] In this embodiment, the third patterning layer 241 exposes the surface of the insulating material film on the initial second region B.

[0120] In other embodiments, the third patterned layer exposes the surface of the insulating material film on the initial first region.

[0121] Please refer to Figure 11 Using the third patterned layer 241 as a mask, the insulating material film 240 is modified.

[0122] The modification treatment includes one or a combination of physical modification and chemical modification.

[0123] In this embodiment, the modification process used is physical modification.

[0124] In this embodiment, the physical modification method is a chemical etching process, and the parameters of the chemical etching process include: a low-concentration acidic solution, and the acidic solution includes: hydrochloric acid.

[0125] In other embodiments, the modification treatment may also be chemical modification.

[0126] In this embodiment, after the chemical etching process, the thickness of the insulating material film 240 on the initial first region A is different from the thickness of the insulating material film 240 on the initial second region B.

[0127] In other embodiments, the physical modification method is a chemical etching process, or the modification treatment may also be chemical modification.

[0128] In one embodiment, after the modification treatment, the roughness of the insulating material film on the initial first region is different from the roughness of the insulating material film on the initial second region.

[0129] In another embodiment, after the modification treatment, the insulating material film on the initial first region is made of magnesium oxide, and the insulating material film on the initial second region is made of magnesium oxide doped with a second modifying ion, wherein the second modifying ion includes one or more combinations of nitrogen ions or magnesium ions.

[0130] In this embodiment, after modifying the insulating material film 240, the third patterned layer 241 is removed.

[0131] In other embodiments, the insulating material film may not be modified, and the insulating material film on the initial first region may be the same as the insulating material film on the initial second region.

[0132] Please refer to Figure 12 A second electromagnetic material film 250 is formed on the surface of the insulating material film 240.

[0133] The second electromagnetic material film 250 is formed by physical vapor deposition or chemical vapor deposition.

[0134] The material of the second electromagnetic material film 250 includes one or a combination of iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron, and lanthanum strontium manganese oxide.

[0135] In this embodiment, the material of the second electromagnetic material film 250 is cobalt iron boron.

[0136] Next, the second electromagnetic material film 250 is modified. For details of the modification process, please refer to [reference needed]. Figures 13 to 14 .

[0137] Please refer to Figure 13 A fourth patterned layer 251 is formed on the surface of the second electromagnetic material film 250; the fourth patterned layer 251 exposes the surface of the second electromagnetic material film 250 on the initial first region A or the initial second region B.

[0138] In this embodiment, the fourth patterning layer 251 exposes the surface of the second electromagnetic material film 250 on the initial second region B.

[0139] In other embodiments, the fourth patterned layer exposes the surface of the second electromagnetic material film on the initial first region.

[0140] Please refer to Figure 14 Using the fourth patterned layer 251 as a mask, the second electromagnetic material film 250 is modified.

[0141] The modification treatment includes one or a combination of physical modification and chemical modification.

[0142] In this embodiment, the modification treatment used is chemical modification.

[0143] In this embodiment, the chemical modification method is plasma doping treatment, and the doped ions include titanium ions or tantalum ions.

[0144] In this embodiment, after the plasma doping treatment, the material of the second electromagnetic material film 250 on the initial first region A is cobalt iron boron, and the material of the second electromagnetic material film 250 on the initial second region B is cobalt iron boron doped with a third modified ion, which is titanium ion.

[0145] In another embodiment, the chemical modification method is a chemical solution treatment. The solution used for chemical modification is a hydrogen peroxide solution, the material of the second electromagnetic material film on the initial first region is cobalt-iron-boron, and the material of the second electromagnetic material film on the initial second region is partially oxidized oxygen-containing cobalt-iron-boron.

[0146] In other embodiments, the modification process may also be physical modification, which includes plasma etching or chemical etching processes.

[0147] In another embodiment, after the modification treatment, the roughness of the second electromagnetic material film on the initial first region is different from the roughness of the second electromagnetic material film on the initial second region.

[0148] In another embodiment, after the modification treatment, the thickness of the second electromagnetic material film on the initial first region is different from the thickness of the second electromagnetic material film on the initial second region.

[0149] In this embodiment, after modifying the second electromagnetic material film 250, the fourth patterned layer 251 is removed.

[0150] In other embodiments, the second electromagnetic material film may not be modified, and the second electromagnetic material film on the initial first region may be the same as the second electromagnetic material film on the initial second region.

[0151] Please refer to Figure 15 An optimized material film 260 is formed on the surface of the second electromagnetic material film 250.

[0152] The optimized material film 260 can better match the lattice of the second electromagnetic material film 250, thereby improving the performance of the formed magnetic tunnel junction.

[0153] The formation process of the optimized material film 260 includes physical vapor deposition or chemical vapor deposition.

[0154] The material of the optimized material film 260 includes one or a combination of magnesium oxide, aluminum oxide, silicon nitride, silicon oxynitride, hafnium dioxide, and zirconium dioxide.

[0155] In this embodiment, the optimized material film 260 is made of magnesium oxide. In this embodiment, the optimized material film 260 on the initial first region A and the optimized material film 260 on the initial second region B are the same.

[0156] In other embodiments, the method for forming the semiconductor structure further includes: modifying the optimized material film to make the optimized material film on the initial first region different from the optimized material film on the initial second region.

[0157] In one embodiment, the thickness of the optimized material film on the initial first region is different from the thickness of the optimized material film on the initial second region.

[0158] In another embodiment, the roughness of the optimized material film on the initial first region is different from the roughness of the optimized material film on the initial second region.

[0159] In another embodiment, the material of the optimized material film on the initial first region is magnesium oxide, and the material of the optimized material film on the initial second region is magnesium oxide doped with a fifth modified ion, wherein the fifth modified ion includes magnesium ions or nitrogen ions.

[0160] Please refer to Figure 16 An upper electrode material film 270 is formed on the surface of the optimized material film 260.

[0161] The formation process of the upper electrode material film 270 includes physical vapor deposition or chemical vapor deposition.

[0162] The material of the upper electrode material film 270 includes one or a combination of titanium, tantalum, platinum, copper, tungsten, aluminum, titanium nitride, tantalum nitride, and tungsten silicide.

[0163] In this embodiment, the material of the upper electrode material film 270 is tungsten.

[0164] In this embodiment, the upper electrode material film 270 on the initial first region A is the same as the upper electrode material film 270 on the initial second region.

[0165] In other embodiments, the method for forming the semiconductor structure further includes: modifying the upper electrode material film to make the upper electrode material film on the initial first region different from the upper electrode material film on the initial second region.

[0166] In one embodiment, the thickness of the upper electrode material film on the initial first region is different from the thickness of the upper electrode material film on the initial second region.

[0167] In another embodiment, the roughness of the upper electrode material film on the initial first region is different from the roughness of the upper electrode material film on the initial second region.

[0168] In another embodiment, the material of the upper electrode material film on the initial first region is tungsten, and the material of the upper electrode material film on the initial second region is tungsten doped with a seventh modified ion, which includes titanium ions or tantalum ions.

[0169] Next, using a patterning process, the first electromagnetic material film 230, the insulating material film 240, and the second electromagnetic material film 250 are etched until the surface of the substrate 200 is exposed, forming the magnetic tunnel junction on the substrate 200. The first region of the magnetic tunnel junction is located on a portion of the initial first region A, and the second region of the magnetic tunnel junction is located on a portion of the initial second region B. The magnetic tunnel junction includes: a first electromagnetic layer, an insulating layer located on the first electromagnetic layer, and a second electromagnetic layer located on the insulating layer. For details of the patterning process, please refer to [link to relevant documentation]. Figures 17 to 18 .

[0170] Please refer to Figure 17 A first patterned layer 280 is formed on the second electromagnetic material film 250, and the first patterned layer 280 exposes a portion of the second electromagnetic material film.

[0171] In this embodiment, the first patterning layer 280 exposes the surface of the upper electrode material film 270 on a portion of the initial first region A and a portion of the initial second region B, and the first patterning layer 280 covers the surface of the upper electrode material film 270 on a portion of the initial first region A and a portion of the initial second region B.

[0172] Please refer to Figure 18 Using the first patterned layer 280 as a mask, the first electromagnetic material film 230, the insulating material film 240, and the second electromagnetic material film 250 are etched until the surface of the substrate 200 is exposed.

[0173] In this embodiment, using the first patterned layer 280 as a mask, the lower electrode material film 210, seed material film 220, first electromagnetic material film 230, insulating material film 240, second electromagnetic material film 250, optimized material film 260, and upper electrode material film 270 are etched until the surface of the substrate 200 is exposed. This allows the lower electrode material film 210 to form the lower electrode layer 212, the seed material film 220 to form the seed layer 222, the first electromagnetic material film 230 to form the first electromagnetic layer 232, and the insulating material film 270 to form the upper electrode layer 270. Film 240 forms an insulating layer 242, second electromagnetic material film 250 forms a second electromagnetic layer 252, optimized material film 260 forms an optimized layer 262, and upper electrode material film 270 forms an upper electrode layer 272, thereby forming a magnetic tunnel junction 290 on substrate 200. The magnetic tunnel junction 290 includes adjacent first region I and second region II, and the first region I of the magnetic tunnel junction 290 is located on a portion of the initial first region A, and the second region II of the magnetic tunnel junction 290 is located on the portion of the initial second region B.

[0174] In other embodiments, the magnetic tunnel junction further includes a third region adjacent to the first and second regions, wherein at least one material layer on the third region is different from the material layers of the first and second regions.

[0175] By forming a magnetic tunnel junction 290 on a substrate 200, the magnetic tunnel junction 290 includes adjacent first region I and second region II, and at least one material layer of the first region I and the material layer of the second region II are different, so that the multilayer material layers of the first region I and the multilayer material layers of the second region have different high resistance and low resistance values, respectively, and the magnetic resistance between the first region I and the second region II is connected in parallel, so that the magnetic tunnel junction 290 can form 2^ n This allows for the creation of multiple states (n being a natural number greater than 1), thereby effectively increasing the storage capacity of a single memory cell and consequently improving the capacity density of the resulting semiconductor structure.

[0176] Accordingly, this invention also provides a semiconductor structure formed using the above method. Please refer to [link / reference needed]. Figure 18 The system includes: a substrate 200; a magnetic tunnel junction 290 located on the substrate 200, the magnetic tunnel junction 290 including adjacent first region I and second region II, the magnetic tunnel junction 290 including multiple layers of material overlapping along the normal direction of the substrate 200, and at least one layer of material in the first region I and the layer of material in the second region II are different.

[0177] Since the magnetic tunnel junction 290 includes adjacent first region I and second region II, and at least one material layer in the first region I and the material layers in the second region II are different, the multiple material layers in the first region I and the multiple material layers in the second region II have different high resistance and low resistance values, respectively. Furthermore, the magnetic resistances of the first region I and the second region II are connected in parallel, allowing the magnetic tunnel junction 290 to form a 2^ n This allows for the creation of multiple states (n being a natural number greater than 1), thereby effectively increasing the storage capacity of a single memory cell and consequently improving the capacity density of the resulting semiconductor structure.

[0178] The different material layers are due to differences in physical or chemical properties.

[0179] In other embodiments, the magnetic tunnel junction further includes a third region adjacent to the first and second regions, wherein at least one material layer in the third region is different from the material layers in the first and second regions.

[0180] In this embodiment, the multilayer material layer includes: a first electromagnetic layer 232, an insulating layer 242 located on the surface of the first electromagnetic layer 232, and a second electromagnetic layer 252 located on the surface of the insulating layer 242.

[0181] In this embodiment, the thickness of the first electromagnetic layer 232 in the first region I is different from the thickness of the first electromagnetic layer 232 in the second region II.

[0182] In another embodiment, the roughness of the first electromagnetic layer in the first region is different from the roughness of the first electromagnetic layer in the second region 2.

[0183] In another embodiment, the material of the first electromagnetic layer in the first region is cobalt iron boron, and the material of the first electromagnetic layer in the second region is cobalt iron boron doped with a first modified ion, the first modified ion including titanium ions or tantalum ions.

[0184] In this embodiment, the thickness of the insulating layer 242 in the first region I is different from the thickness of the insulating layer 242 in the second region II.

[0185] In another embodiment, the roughness of the insulating layer in the first region is different from that in the insulating layer in the second region.

[0186] In another embodiment, the insulating layer of the first region is made of magnesium oxide, and the insulating layer of the second region is made of magnesium oxide doped with a second modified ion, the second modified ion including nitrogen ions or magnesium ions.

[0187] In this embodiment, the material of the second electromagnetic layer 252 in the first region I is cobalt iron boron, and the material of the second electromagnetic layer 252 in the second region II is cobalt iron boron doped with a third ion, wherein the third modified ion includes titanium ions or tantalum ions.

[0188] In another embodiment, the thickness of the second electromagnetic layer in the first region is different from the thickness of the second electromagnetic layer in the second region.

[0189] In another embodiment, the roughness of the second electromagnetic layer in the first region is different from that of the second electromagnetic layer in the second region.

[0190] In this embodiment, the multilayer material layer further includes a seed layer 222 located at the bottom of the first electromagnetic layer 232.

[0191] In this embodiment, the seed layer 222 of the first region I and the seed layer of the second region II are the same.

[0192] In another embodiment, the thickness of the seed layer in the first region is different from the thickness of the seed layer in the second region.

[0193] In another embodiment, the roughness of the seed layer in the first region is different from that in the seed layer in the second region.

[0194] In another embodiment, the seed layer of the first region is made of cobalt iron boron, and the seed layer of the second region is made of cobalt iron boron doped with a fourth modified ion, which includes titanium ions or tantalum ions.

[0195] In this embodiment, the multilayer material layer further includes an optimization layer 262 located on the second electromagnetic layer 252.

[0196] In this embodiment, the optimization layer 262 of the first region I and the optimization layer 262 of the second region II are the same.

[0197] In other embodiments, the thickness of the optimization layer in the first region is different from the thickness of the optimization layer in the second region.

[0198] In another embodiment, the roughness of the optimization layer in the first region is different from that in the optimization layer in the second region.

[0199] In another embodiment, the material of the optimized layer in the first region is magnesium oxide, and the material of the optimized layer in the second region is magnesium oxide doped with a fifth modified ion, wherein the fifth modified ion includes magnesium ions or nitrogen ions.

[0200] In this embodiment, the multilayer material layer further includes: a lower electrode layer 212 located at the bottom of the first electromagnetic layer 232 and an upper electrode layer 272 located on the second electromagnetic layer 252.

[0201] Specifically, in this embodiment, the seed layer 222 is located on the surface of the lower electrode layer 212, and the upper electrode layer 272 is located on the surface of the optimization layer 262.

[0202] In this embodiment, the lower electrode layer 212 of the first region I and the lower electrode layer 212 of the second region II are the same.

[0203] In another embodiment, the thickness of the lower electrode layer in the first region is different from the thickness of the lower electrode layer in the second region.

[0204] In another embodiment, the roughness of the lower electrode layer in the first region is different from that in the lower electrode layer in the second region.

[0205] In another embodiment, the material of the lower electrode layer of the first region is tungsten, and the material of the lower electrode layer of the second region is tungsten doped with a sixth modified ion, the sixth modified ion including titanium ions or tantalum ions.

[0206] In this embodiment, the upper electrode layer 272 of the first region I and the upper electrode layer 272 of the second region II are the same.

[0207] In other embodiments, the thickness of the upper electrode layer in the first region is different from the thickness of the upper electrode layer in the second region.

[0208] In another embodiment, the roughness of the upper electrode layer in the first region is different from that in the upper electrode layer in the second region.

[0209] In another embodiment, the material of the upper electrode layer of the first region is tungsten, and the material of the upper electrode layer of the second region is tungsten doped with a seventh modified ion, which includes titanium ions or tantalum ions.

[0210] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A semiconductor structure, characterized in that, include: Base; The magnetic tunnel junction is located on the substrate, and the same magnetic tunnel junction includes adjacent first and second regions. Each magnetic tunnel junction includes multiple layers of material overlapping along the normal direction of the substrate, and the material of at least one layer of material in the first region and the material of the second region in the same magnetic tunnel junction are different. The substrate includes a plurality of initial first regions, with an initial second region between adjacent initial first regions, and the initial second regions and the initial first regions are adjacent; the first region of the magnetic tunnel junction is located on a portion of the initial first regions, the second region of the magnetic tunnel junction is located on a portion of the initial second regions, and the magnetic tunnel junction includes: a first electromagnetic layer, an insulating layer located on the first electromagnetic layer, and a second electromagnetic layer located on the insulating layer; The method for forming the multilayer material layer includes: forming a first electromagnetic material film on the initial first region and the initial second region; forming an insulating material film on the first electromagnetic material film; forming a second electromagnetic material film on the insulating material film; and using a patterning process to etch the first electromagnetic material film, the insulating material film, and the second electromagnetic material film until the substrate surface is exposed, thereby forming the magnetic tunnel junction on the substrate.

2. The semiconductor structure as described in claim 1, characterized in that, The thickness of the first electromagnetic layer in the first region is different from the thickness of the first electromagnetic layer in the second region.

3. The semiconductor structure as described in claim 1, characterized in that, The roughness of the first electromagnetic layer in the first region is different from that of the first electromagnetic layer in the second region.

4. The semiconductor structure as described in claim 1, characterized in that, The material of the first electromagnetic layer in the first region includes cobalt iron boron, and the material of the first electromagnetic layer in the second region includes cobalt iron boron doped with a first modified ion, wherein the first modified ion includes titanium ions or tantalum ions.

5. The semiconductor structure as described in claim 1, characterized in that, The thickness of the insulating layer in the first region is different from the thickness of the insulating layer in the second region.

6. The semiconductor structure as described in claim 1, characterized in that, The roughness of the insulating layer in the first region is different from that in the second region.

7. The semiconductor structure as described in claim 1, characterized in that, The insulating layer of the first region is made of magnesium oxide, and the insulating layer of the second region is made of magnesium oxide doped with a second modified ion, which includes nitrogen ions or magnesium ions.

8. The semiconductor structure as described in claim 1, characterized in that, The thickness of the second electromagnetic layer in the first region is different from the thickness of the second electromagnetic layer in the second region.

9. The semiconductor structure as described in claim 1, characterized in that, The roughness of the second electromagnetic layer in the first region is different from that of the second electromagnetic layer in the second region.

10. The semiconductor structure as claimed in claim 1, characterized in that, The material of the second electromagnetic layer in the first region includes cobalt iron boron, and the material of the second electromagnetic layer in the second region includes cobalt iron boron doped with a third modified ion, wherein the third modified ion includes titanium ions or tantalum ions.

11. The semiconductor structure as claimed in claim 1, characterized in that, The multilayer material layer also includes a seed layer located at the bottom of the first electromagnetic layer.

12. The semiconductor structure as claimed in claim 11, characterized in that, The thickness of the seed layer in the first region is different from that in the second region.

13. The semiconductor structure as described in claim 11, characterized in that, The roughness of the seed layer in the first region is different from that in the seed layer in the second region.

14. The semiconductor structure as claimed in claim 11, characterized in that, The seed layer material of the first region includes cobalt iron boron, and the seed layer material of the second region includes cobalt iron boron doped with a fourth modified ion, wherein the fourth modified ion includes titanium ions or tantalum ions.

15. The semiconductor structure as claimed in claim 1, characterized in that, The multilayer material layer also includes an optimization layer located on the second electromagnetic layer.

16. The semiconductor structure as claimed in claim 15, characterized in that, The thickness of the optimization layer in the first region is different from the thickness of the optimization layer in the second region.

17. The semiconductor structure as claimed in claim 15, characterized in that, The roughness of the optimization layer in the first region is different from that in the optimization layer in the second region.

18. The semiconductor structure as claimed in claim 15, characterized in that, The material of the optimized layer in the first region includes cobalt iron boron, and the material of the optimized layer in the second region includes cobalt iron boron doped with a fifth modified ion, wherein the fifth modified ion includes nitrogen ions or magnesium ions.

19. The semiconductor structure as claimed in claim 1, characterized in that, The multilayer material layer further includes: a lower electrode layer located at the bottom of the first electromagnetic layer and an upper electrode layer located on the second electromagnetic layer.

20. The semiconductor structure as claimed in claim 19, characterized in that, The thickness of the lower electrode layer in the first region is different from the thickness of the lower electrode layer in the second region.

21. The semiconductor structure as described in claim 19, characterized in that, The roughness of the lower electrode layer in the first region is different from that in the lower electrode layer in the second region.

22. The semiconductor structure as described in claim 19, characterized in that, The material of the lower electrode layer in the first region includes a metal, and the material of the lower electrode layer in the second region includes a metal doped with a sixth modified ion, wherein the sixth modified ion includes a titanium ion or a tantalum ion.

23. The semiconductor structure as described in claim 19, characterized in that, The thickness of the upper electrode layer in the first region is different from the thickness of the upper electrode layer in the second region.

24. The semiconductor structure as claimed in claim 19, characterized in that, The roughness of the upper electrode layer in the first region is different from that in the upper electrode layer in the second region.

25. The semiconductor structure as claimed in claim 19, characterized in that, The material of the upper electrode layer in the first region includes a metal, and the material of the upper electrode layer in the second region includes a metal doped with a seventh modified ion, wherein the seventh modified ion includes a titanium ion or a tantalum ion.

26. The semiconductor structure as claimed in claim 1, characterized in that, The magnetic tunnel junction further includes a third region adjacent to the first and second regions, wherein at least one material layer in the third region is different from the material layers in the first and second regions.

27. A method for forming a semiconductor structure, characterized in that, include: Provide a base; A magnetic tunnel junction is formed on the substrate. The same magnetic tunnel junction includes adjacent first and second regions. Each magnetic tunnel junction includes multiple layers of material overlapping along the normal direction of the substrate. At least one material layer of the first region and the material layer of the second region are different within the same magnetic tunnel junction. The substrate includes a plurality of initial first regions, with initial second regions between adjacent initial first regions, and the initial second regions and initial first regions are adjacent to each other; the method for forming the multilayer material layer includes: forming a first electromagnetic material film on the initial first regions and initial second regions; forming an insulating material film on the first electromagnetic material film; forming a second electromagnetic material film on the insulating material film; using a patterning process, etching the first electromagnetic material film, the insulating material film and the second electromagnetic material film until the substrate surface is exposed, and forming the magnetic tunnel junction on the substrate; the first region of the magnetic tunnel junction is located on a portion of the initial first regions, the second region of the magnetic tunnel junction is located on a portion of the initial second regions, and the magnetic tunnel junction includes: a first electromagnetic layer, an insulating layer located on the first electromagnetic layer and a second electromagnetic layer located on the insulating layer.

28. The method for forming a semiconductor structure as described in claim 27, characterized in that, The patterning process includes: forming a first patterned layer on the second electromagnetic material film, wherein the first patterned layer exposes a portion of the second electromagnetic material film; using the first patterned layer as a mask, etching the first electromagnetic material film, the insulating material film, and the second electromagnetic material film until the substrate surface is exposed.

29. The method for forming a semiconductor structure as described in claim 27, characterized in that, The method for forming the multilayer material layer further includes: modifying at least one of the first electromagnetic material film, the insulating material film, and the second electromagnetic material film.

30. The method for forming a semiconductor structure as described in claim 29, characterized in that, The modification process includes: forming a second patterned layer on the surface of the first electromagnetic material film; exposing the surface of the first electromagnetic material film on the initial first region or the initial second region on the second patterned layer; and modifying the first electromagnetic material film using the second patterned layer as a mask.

31. The method for forming a semiconductor structure as described in claim 29, characterized in that, The modification process includes: forming a third patterned layer on the surface of the insulating material film; exposing the surface of the insulating material film on the initial first region or the initial second region by the third patterned layer; and modifying the insulating material film using the third patterned layer as a mask.

32. The method for forming a semiconductor structure as described in claim 29, characterized in that, The modification process includes: forming a fourth patterned layer on the surface of the second electromagnetic material film; the fourth patterned layer exposing the surface of the second electromagnetic material film on the initial first region or the initial second region; and using the fourth patterned layer as a mask to modify the second electromagnetic material film.

33. The method for forming a semiconductor structure as described in claim 29, characterized in that, The modification treatment includes one or a combination of physical modification and chemical modification.

34. The method for forming a semiconductor structure as described in claim 33, characterized in that, The physical modification method includes plasma etching.

35. The method for forming a semiconductor structure as described in claim 33, characterized in that, The physical modification method includes: chemical etching process.

36. The method for forming a semiconductor structure as described in claim 33, characterized in that, The chemical modification method includes: plasma doping treatment, wherein the doped ions include: titanium ions, magnesium ions, nitrogen ions, or magnesium ions.

37. The method for forming a semiconductor structure as described in claim 33, characterized in that, The chemical modification method includes: chemical solution treatment.

38. The method for forming a semiconductor structure as described in claim 33, characterized in that, The method for forming the multilayer material layer further includes: forming a seed material film on the substrate before forming the first electromagnetic material film; the patterning process further etches the seed material film to form a seed layer in a first region and a second region.

39. The method for forming a semiconductor structure as described in claim 38, characterized in that, Also includes: After the seed material film is formed but before the patterning process, the seed material film is modified to make the seed material films on the initial first region and the initial second region different.

40. The method for forming a semiconductor structure as described in claim 27, characterized in that, The method for forming the multilayer material layer further includes: after forming the second electromagnetic material film, forming an optimized material film on the surface of the second electromagnetic material film; and etching the optimized material film by the patterning process to form an optimized layer in the first region and the second region.

41. The method for forming a semiconductor structure as described in claim 40, characterized in that, Also includes: After the optimized material film is formed but before the patterning process, the optimized material film is modified to make the optimized material film on the initial first region and the initial second region different.

42. The method for forming a semiconductor structure as described in claim 27, characterized in that, The method for forming the multilayer material layer further includes: forming a lower electrode material film on the substrate before forming the first electromagnetic material film; forming an upper electrode material film on the second electromagnetic material film after forming the second electromagnetic material film; the patterning process further etches the lower electrode material film and the upper electrode material film to form a lower electrode layer and an upper electrode layer in a first region and a second region, wherein the lower electrode layer is located at the bottom of the first electromagnetic layer and the upper electrode layer is located on the second electromagnetic layer.

43. The method for forming a semiconductor structure as described in claim 42, characterized in that, Also includes: The lower electrode material film is modified so that the materials of the lower electrode material film on the initial first region and the initial second region are different.

44. The method for forming a semiconductor structure as described in claim 42, characterized in that, Also includes: The upper electrode material film is modified so that the materials of the upper electrode material film on the initial first region and the initial second region are different.

45. The method for forming a semiconductor structure as described in claim 27, characterized in that, The magnetic tunnel junction further includes a third region adjacent to the first and second regions, wherein at least one material layer on the third region is different from the material layers of the first and second regions.

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